var fs=require('fs');

fs.open('read.txt','r', function oppend(err,fd) {

    if(err)throw err;

    var buffer=new Buffer(10),offset=0,length=buffer.length,pos=100;

    fs.read(fd,buffer,0,4,0, function read(err,bytes) {
        if(err)throw err;

        console.log('buffer:',buffer.toString());
        console.log('bytes:',bytes.toString());

    });

});